通讯机构：
[Zhonghua Liu; Chengwen Shen] K;Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, Hunan, 410128, China<&wdkj&>National Research Center of Engineering & Technology for Utilization of Functional Ingredients from Botanicals, Collaborative Innovation Center of Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, Hunan, 410128, China
摘要：
Fuzhuan brick tea (FBT), one of the unique dark teas, has various health-promoting functions. In the present study, one polysaccharide fraction, namely FBTPS-2-1, was extracted and purified from FBT, and its structure and potential immunostimulatory activity were investigated. The results showed that FBTPS-2-1,one of typical heteropolysaccharides, was mainly composed of Gal, Ara, and Glc with little molar content of Man, Rha, GalA, and GlcA in molar ratio of 46.59:22.13:13.57:8.20:6.02:2.12:1.38 and molecular weight of 748 kDa. The backbone of FBTPS-2-1 contained -> 4)-beta-D-Galp-(1 -> 4)-beta-D-Galp-(1 ->, -> 4)-beta-D-Galp-(1 -> 4)-alpha-D-Glcp-(1 ->, -> 4)-alpha-D-Glcp-(1 -> 4)-alpha-D-Glcp- (1 ->, -> 4)-alpha-D-Glcp-(1 -> 4)-beta-D-Galp-(1 ->, -> 3)-beta-D-Galp-(1 -> 4)-beta-D-Galp-(1 ->, -> 3,6)-beta-D-Galp- (1 -> 3)-beta-D-Galp- (1 -> and -> 3,6)-beta-D-Galp-(1 -> 3,6)-beta-D-Galp-(1 ->. The linkages of branches in FBTPS-2-1 were mainly composed of alpha-L-Araf-(1 -> 3,6)-beta-D-Galp-(1 ->, -> 5)-alpha-L-Araf-(1 -> 3,6)-beta-D-Galp-(1 ->, -> 6)-beta-D-Galp41 -> 3,6)-beta-D-Galp-(1 ->, alpha-L-Araf-(1 -> 3,S)-alpha-L-Araf-(1 ->, -> 3,5)-alpha-L-Araf- (1 -> 5)-alpha-L-Araf-(1 ->, alpha-D-Galp-(1->3,5)-alpha-L-Araf-(1 -> and -> 5)-alpha-L-Araf-(1 -> 6)-beta-D-Galp-(1 ->. Furthermore, FBTPS-2-1 could increase the phagocytosis of macrophages and promote the secretion of NO and a variety of inflammatory cytokines, including TNF-alpha, IL-1 beta, and IL-6, indicating noticeable immune enhancement activity. Thus, FBTPS-2-1 could serve as a potentially functional food to improve human health by modulating the host immunoreaction.
期刊：
现代食品科技,2020年36(8):48-55 and 264 ISSN：1673-9078
作者机构：
湖南农业大学茶学教育部重点实验室,湖南长沙410128;广东省农业科学院茶叶研究所,广东省茶树资源创新利用重点实验室,广东广州510640;湖南农业大学国家植物功能成分利用工程技术研究中心,湖南长沙410128;广东省茶叶收藏与鉴赏协会,广东广州510640;[乔小燕] Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, 410128, China<&wdkj&>Tea Research Institute, Guangdong Provincial Key Laboratory of Tea Plant Resources Innovation & Utilization, Guangdong Academy of Agricultural Science, Guangzhou, 510640, China<&wdkj&>National Research Center of Engineering Technologies for Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, 410128, China
摘要：
以1979-2019年WOS(Web of science)和CNKI(China national knowledge infrastructure)收录的茶叶香气品质相关文献为研究对象,采用CiteSpace文献计量方法分别从年代、作者、机构、国家、研究热点、演进趋势等方面进行归纳统计分析。结果表明,2006年以后相关研究文献呈显著增长趋势,目前已形成稳定的核心作者群,但各群体间的合作研究相对较少;在该研究领域,我国影响力最大,其次是日本和美国;热点研究内容主要集中在香气形成机理、香气物质提取方法、检测手段及关键香气物质等方面。综上结果,结合时区图谱,进一步指出茶叶香气的研究历程及目前所处的发展阶段。
摘要：
The MYB proteins belong to a large family of transcription factors in plant genomes and play significant roles in primary and secondary metabolism. Although several CsMYB genes have been identified in Camellia sinensis, few CsMYBs involved in L-theanine biosynthesis have been analyzed. In this study, we screened and identified 20 CsMYBs related to L-theanine biosynthesis. Transcriptomic analysis revealed that the expression profiles of the CsMYBs were positively or negatively related to dynamic changes in the L-theanine content. Validation of selected L-theanine biosynthetic and CsMYB genes was conducted by qRT-PCR. The results illustrated that most of the structural and CsMYB genes were downregulated with a decrease in the L-theanine levels. Protein-protein interaction networks of CsMYB5, CsMYB12 and CsMYB94 proteins demonstrated that they might form complexes with bHLH and WD 40 proteins. Multiple DNA-binding sites of the R2R3-MYB protein were observed in promoter regions of structural genes, indicating CsMYB family proteins might be involved in L-theanine metabolism via the attachment of AC elements. Moreover, CsMYB73 demonstrated binding specificity to the promoter region of CsGDH2 (CsGDH2-pro). These findings provide fundamental understanding of specific members of the CsMYBs related to the L-theanine biosynthesis pathway. (C) 2020 Published by Elsevier B.V.
摘要：
The distinct historical background and tea flavor, including high umami taste and low astringency, make the albino tea plants (Atps) stick out from the tea plant (Camellia sinesnis). The decipherment of genes, enzymes, and metabolites involved in these processes is still significantly lagging, which lays an obstacle for molecular plant breeding and commercialized production. With the popularity of high-throughput omics technology, 'single level' or 'multi-level'-based research theory have emerged as powerful tools for revealing the mechanism of characteristic metabolite accumulation and pigment transformation. Thus, it is pivotal to summarize and introduce these advances in facilitating gene identification of critical pathways in the Atps. In this review, we systematically arranged the history and classification of Atps, detailed their strategies for stress response and the metabolic pattern of L-theanine and catechins. Further, reference the successful examples of model plants, we concentrating on the recent advances in omics technology applied to the Atps. Finally, we prospect the promising development areas of the Atps.
通讯机构：
[Liu, ZH; Zhu, MZ; Wang, Qi-ye] H;Hunan Agr Univ, Coll Hort, Natl Res Ctr Engn Technol Utilizat Funct Ingredie, Key Lab Tea Sci,Minist Educ, Changsha 410128, Peoples R China.;Hunan Normal Univ, Coll Life Sci, Hunan Prov Key Lab Anim Intestinal Funct & Regula, Hunan Int Joint Lab Anim Intestinal Ecol & Hlth, Changsha 410081, Peoples R China.
关键词：
Dark tea;Gastrointestinal function;Gastrointestinal transit;Antibiotic;Restoration;Intestinal microbes
摘要：
Processing of dark tea varieties, such as Fu brick tea, Liupao tea, Qianliang tea, and Qing brick tea, includes solid-state fermentation involving microorganisms. In this study, we analyzed the major chemical constituents of dark tea extracts and evaluated their modulatory effect on the gastrointestinal function in normal mice, including the improvement of gastrointestinal transit and intestinal microbial, as well as the attenuation of intestinal microbial dysbiosis and intestinal pathological damage, and the adjustment of immune function in antibiotic-treated mice. Substantial differences in major chemical constituents, including total polyphenols, total organic acids, water extract content, 18 free amino acids, gallic acid, and six tea catechins, were observed among Fu brick tea, Qianliang tea, Qing brick tea, and Liupao tea extracts. Extracts from the four dark tea varieties significantly promoted gastrointestinal transit and colonization of beneficial Bifidobacterium and Lactobacillus, and inhibited the growth of harmful Escherichia coli and Enterococcus in normal mice. In addition, Qianliang tea, Qing brick tea, and Liupao tea extracts significantly accelerated the reversal of the ampicillin sodium-induced pathological damage in the ileum, intestinal bacterial dysbiosis (Bifidobacterium, Lactobacillus, E. coli, and Enterococcus), and low immunity.
关键词：
amino acid;catechin;gallocatechin;glutamic acid derivative;glycoside;kaempferol;kaempferol derivative;theanine;Camellia sinensis;chemistry;growth, development and aging;liquid chromatography;metabolism;metabolome;metabolomics;plant leaf;shoot;tandem mass spectrometry;Amino Acids;Camellia sinensis;Catechin;Chromatography, Liquid;Glutamates;Glycosides;Kaempferols;Metabolome;Metabolomics;Plant Leaves;Plant Shoots;Tandem Mass Spectrometry
摘要：
<jats:sec><jats:title>Abstract</jats:title><jats:p>‘Anji Baicha’ (<jats:italic>Camellia sinensis</jats:italic>) is a low‐temperature‐sensitive tea variety. During the development of young shoots, the leaves of ‘Anji Baicha’ exhibit periodic albinism. The quality of ‘Anji Baicha’ is closely related to the color of the fresh leaves, with whiter leaves affording a higher amino acid content and superior sensory quality after processing. However, the metabolic mechanism of its quality formation is still unclear. In this study, we analyzed the metabolomic changes of young shoots of ‘Anji Baicha’ and screened for metabolic markers that may be involved in the periodic albinism. Positive‐ and negative‐mode UPLC‐QTOF‐MS was applied to the metabolomic analysis of young leaves of ‘Anji Baicha’ during three developmental stages (i.e., the pre‐albescent, albescent, and regreening stages). The results revealed significant differences in the metabolic profiles of the young leaves at the three stages. The differential metabolites were mainly related to the pathways of flavonoid, phenylpropanoid, and amino acid biosynthesis. The concentrations of several amino acids (primarily <jats:sc>l</jats:sc>‐theanine, <jats:sc>l</jats:sc>‐glutamate, N<jats:sub>2</jats:sub>‐acetyl‐<jats:sc>l</jats:sc>‐ornithine, <jats:sc>l</jats:sc>‐aspartic acid, <jats:sc>d</jats:sc>‐proline, <jats:sc>l</jats:sc>‐glutamine, <jats:sc>l</jats:sc>‐leucine, and pyroglutamic acid) and 12‐OPDA were significantly higher in the albescent stage. In contrast, during the albescent stages, the concentrations of several carbohydrates (<jats:sc>d</jats:sc>‐fructose, β‐<jats:sc>d</jats:sc>‐galactopyranose, 3‐<jats:italic>O</jats:italic>‐fucopyranosyl‐2‐acetamido‐2‐deoxyglucopyranose, galactose‐β‐1, 4‐xylose acetyl‐maltose, and 2‐fucosyllactose) were significantly lower. Moreover, catechins (mainly epigallocatechin and catechin derivatives), dimeric catechins (primarily proanthocyanidins), and flavonol and flavonol/flavone glycosides (mainly kaempferol, myricetin, quercetin, cyanidin, and delphinidin glycosides) were detected at the highest levels in the regreening or pre‐albescent stages. The obtained results enhance the current understanding of the metabolic mechanisms of periodic albinism and quality development formation in ‘Anji Baicha’.</jats:p></jats:sec><jats:sec><jats:title>Practical Application</jats:title><jats:p>The obtained results not only provide information regarding differential metabolites but also advance the understanding of the mechanism of periodic albinism in ‘Anji Baicha’ at the metabolite level and open up new possibilities for the genetic improvement of tea cultivars.</jats:p></jats:sec>
作者机构：
湖南农业大学茶学教育部重点实验室,湖南 长沙 410128;国家植物功能成分利用工程技术研究中心,湖南 长沙 410128;湖南省植物功能成分利用协同创新中心,湖南 长沙 410128;[周方; 欧阳建] Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, 410128, China<&wdkj&>National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, 410128, China;[黄建安; 刘仲华] Key Laboratory of Tea Science of Ministry of Education, Hunan Agricultural University, Changsha, 410128, China<&wdkj&>National Research Center of Engineering Technology for Utilization of Functional Ingredients from Botanicals, Hunan Agricultural University, Changsha, 410128, China<&wdkj&>Hunan Co-Innovation Center for Utilization of Botanical Functional Ingredients, Changsha, 410128, China
作者机构：
[程晓梅; 李永迪] Tea Key Lab of the Ministry of National Teaching of Hunan Agricultural University, Changsha, 410128, China;National Research Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Changsha, 410128, China;Hunan Co-Innovation Center for Utilization of Botanical Functional Ingredients, Changsha, 410128, China;[杨培迪] Tea Research Institute, Hunan Academy of Agriculture Sciences, Changsha, 410128, China;[李勤; 刘仲华] Tea Key Lab of the Ministry of National Teaching of Hunan Agricultural University, Changsha, 410128, China<&wdkj&>National Research Center of Engineering Technology for Utilization of Botanical Functional Ingredients, Changsha, 410128, China<&wdkj&>Hunan Co-Innovation Center for Utilization of Botanical Functional Ingredients, Changsha, 410128, China
